This International Standard describes two methods for the determination of free formaldehyde (HCHO) in polymer dispersions. The procedure has been evaluated using acrylic, acrylonitrile butadiene, carboxylated styrene-butadiene and vinyl acetate polymer dispersions. Both test methods may also be applicable to polymer dispersions of other compositions.
Method A is the preferred method for polymer dispersions with a free-formaldehyde content higher than 10 mg/kg. Method B is recommended if lower formaldehyde contents have to be determined or arbitration analyses have to be carried out.
Both methods minimize changes in free-formaldehyde concentration that can result from changes in the physical or chemical properties of polymer dispersions.
There are no known limitations to these methods when used in the manner described.